Various color matching techniques have been developed in the past to aid in the selection of the correct matching coating composition to refinish a vehicle, but all suffer from certain significant limitations. For instance, visual tools such as refinish color chips have been used on many occasions to find a suitable match for the vehicle that needs refinishing. However, visual color matching is time-consuming, cumbersome, and subject to many errors as a result of poor lighting conditions, operator variances, and/or variation from the original standard by the paint manufacturer. Another system involves the use of vehicle data, such as its make, model year, and manufacturer's paint code. The vehicle data is used to identify the corresponding coating formulas associated with that paint code.
A further system commonly employed involves the use of a computer controlled colorimeter or spectrophotometer which measures the color values of an undamaged area of the coating on the vehicle and compares these color values to those stored in a database that contains color data for various refinish matching coatings and corresponding matching formulas. From that comparison, the computer locates one or more preliminary matching formulas for the vehicle's original coating color and appearance within an acceptable tolerance. An example of such a method is described in U.S. Pat. No. 7,145,656, entitled “Computer-implemented Method For Matching Paint”, issued Dec. 5, 2006. This method, however, requires measured color values and cannot identify matching formulas based on vehicle identification information.
An even further development is to use both the measured color values and vehicle identifying information to locate potential preliminary matching formulas from a refinish matching coating database. One example of such a system is described in U.S. Pat. No. 6,522,977, entitled “Computer-implemented Method And Apparatus For Matching Paint.” In this system, sample coatings resulting from each of the preliminary matching formulas are prepared and test sprayed. Color match is then visually determined. In most cases, the preliminary matching formulas need to be adjusted manually and repeatedly by trial and error until a match is achieved.
It is known that effect pigment flake orientation is an important contributor to the color and appearance of gonioapparent paint materials. The orientation of the flakes is not always isotropic with respect to a specimen being rotated in its own plane. The process of spraying paint on a vertical surface in the earth's gravitational field may result in preferential orientation, a phenomenon sometimes referred to as the “venetian blind effect”. Such anisotropic specimens are said to be “directional”. This anisotropy is often evidenced by a change in color measurements as the specimen is rotated about its normal surface thus presenting a challenge for vehicle finish repair operations because it is difficult to accurately match the color; i.e. it is difficult to determine the appropriate paint formula that accurately reflects the paint on the vehicle.
When a paint repair is made to a vehicle, a color measuring device such as a goniospectrophotometer, also known as a multi-angle spectrophotometer, is often used to measure the color of the vehicle. The color data obtained from this process is used to select a repair paint formula that will provide the best color match. If the paint on the vehicle is “directional” (i.e. typically a vertical surface), the rotational orientation of the goniospectrophotometer relative to the paint surface normal may have an effect on the appropriate paint formula to select. Currently, color measurement instructions include a description of the proper orientation of the goniospectrophotometer; however, the proper orientation cannot be verified from the measurement data, and without proper orientation, the paint formula selected for repair may not provide an optimal color match. Previous attempts to assure proper orientation are inherently unreliable since there was no known way to confirm proper instrument orientation. Therefore, instrument orientation has not been used as part of the paint formula prediction and retrieval process. Presently there is no quick, easy, and inexpensive way to determine which aftermarket matching refinish coating composition is the best match in color and appearance for a particular OEM coating.
Thus, it would be desirable to provide a system and method for recording the orientation of a color measurement instrument such as a goniospectrometer at the time of vehicle manufacture and include this orientation information as metadata to the color measurement data for later use. It would further be desirable to utilize accelerometers or other orientation sensors in the goniospectrophotometer to record its three-dimensional orientation (i.e. roll, pitch, and yaw) so that an accurate paint formula can be determined and utilized at a later time for repair. It would still further be desirable to record the position (X,Y,Z) of the measurement spot relative to a reference point on the body of the vehicle to confirm the location on the vehicle where the measurement was made